Not really a bug but you will experience a slowdown in game play in one sector due to too many two sided line defs or near visual plain overflow(pushing Doom engine to the max) I you have a pentium you may not notice it. I did on my 486/33.

One of those early maps (November 1995) that is based on the author's workplace. This has all the flaws of that particular genre - far too many tiny, identical rooms, making the gameplay more akin to Rainbow Six than Doom - and the texturing is completely random. Try as I might, I couldn't open the door to the final battle. It's not a very good level at all.

oh yes it is! I found it charming and also quite fun maintaining a foothold, plus the idea that you needed the BFG behind the red door to beat the Spiderdemon was really cool. it plays like Doom - it still has cupboard traps, sniping monsters from elevated positions, the floor strewn with health kits and ammo and what-have-you.